Vehicles are supplied with driver's side airbag modules; generally the driver's side airbag module is located in the center of the steering wheel. This is also the same location where a horn-activating switch has traditionally been mounted.
Various mounting mechanisms have been used for securing the inflatable restraint module to a support structure in a vehicle, such as a steering wheel or dashboard. In one known mounting mechanism, mounting bolts are provided passing from a rear of the support structure and threadably engaging nuts mounted on the inflatable restraint module. In another known mounting mechanism for a vehicle steering wheel, sleeve members mounted to the inflatable restraint module and surrounding the mounting bolts may be forced into contact with a plate forming the supporting structure on a hub portion of the steering wheel to complete a circuit for actuating or activating a horn.
Eventually, the horn-activating switch was adapted for mounting on the underside of the airbag module wherein the module was mounted in a “free floating” arrangement to allow the user to activate the horn by applying an activation pressure to the module and move the driver's side airbag module into a horn activation position. Such horn-activating switches react to a user-applied force to the cover in an effort to sound the horn. For example, and in such a system the entire airbag module moves as force is applied to actuate the horn.
Once attached the module is capable of movement through the application of a user-applied force wherein a horn circuit is completed in accordance with known technologies.
In most vehicles, the electrical path of the horn mechanism runs from the positive lead coming from the column coil, through the horn mechanism, through the steering wheel armature, and “grounding” through the column. In order to prevent this device or any other device mounted on the steering wheel assembly from using an alternative grounding circuit it is desirable to have an isolated ground associated with the horn mechanism.